void EmitCSyms::emitDpiHdr() {
    UINFO(6,__FUNCTION__<<": "<<endl);
    string filename = v3Global.opt.makeDir()+"/"+topClassName()+"__Dpi.h";
    AstCFile* cfilep = newCFile(filename, false/*slow*/, false/*source*/);
    cfilep->support(true);
    V3OutCFile hf (filename);
    m_ofp = &hf;

    m_ofp->putsHeader();
    puts("// DESCR" "IPTION: Verilator output: Prototypes for DPI import and export functions.\n");
    puts("//\n");
    puts("// Verilator includes this file in all generated .cpp files that use DPI functions.\n");
    puts("// Manually include this file where DPI .c import functions are declared to insure\n");
    puts("// the C functions match the expectations of the DPI imports.\n");
    puts("\n");
    puts("#include \"svdpi.h\"\n");
    puts("\n");
    puts("#ifdef __cplusplus\n");
    puts("extern \"C\" {\n");
    puts("#endif\n");
    puts("\n");

    int firstExp = 0;
    int firstImp = 0;
    for (vector<AstCFunc*>::iterator it = m_dpis.begin(); it != m_dpis.end(); ++it) {
	AstCFunc* nodep = *it;
	if (nodep->dpiExportWrapper()) {
	    if (!firstExp++) puts("\n// DPI EXPORTS\n");
	    puts("// DPI Export at "+nodep->fileline()->ascii()+"\n");
	    puts("extern "+nodep->rtnTypeVoid()+" "+nodep->name()+" ("+cFuncArgs(nodep)+");\n");
	}
	else if (nodep->dpiImport()) {
	    if (!firstImp++) puts("\n// DPI IMPORTS\n");
	    puts("// DPI Import at "+nodep->fileline()->ascii()+"\n");
	    puts("extern "+nodep->rtnTypeVoid()+" "+nodep->name()+" ("+cFuncArgs(nodep)+");\n");
	}
    }

    puts("\n");
    puts("#ifdef __cplusplus\n");
    puts("}\n");
    puts("#endif\n");
}
void EmitCSyms::emitDpiImp() {
    UINFO(6,__FUNCTION__<<": "<<endl);
    string filename = v3Global.opt.makeDir()+"/"+topClassName()+"__Dpi.cpp";
    AstCFile* cfilep = newCFile(filename, false/*slow*/, true/*source*/);
    cfilep->support(true);
    V3OutCFile hf (filename);
    m_ofp = &hf;

    m_ofp->putsHeader();
    puts("// DESCR" "IPTION: Verilator output: Implementation of DPI export functions.\n");
    puts("//\n");
    puts("// Verilator compiles this file in when DPI functions are used.\n");
    puts("// If you have multiple Verilated designs with the same DPI exported\n");
    puts("// function names, you will get multiple definition link errors from here.\n");
    puts("// This is an unfortunate result of the DPI specification.\n");
    puts("// To solve this, either\n");
    puts("//    1. Call "+topClassName()+"::{export_function} instead,\n");
    puts("//       and do not even bother to compile this file\n");
    puts("// or 2. Compile all __Dpi.cpp files in the same compiler run,\n");
    puts("//       and #ifdefs already inserted here will sort everything out.\n");
    puts("\n");

    puts("#include \""+topClassName()+"__Dpi.h\"\n");
    puts("#include \""+topClassName()+".h\"\n");
    puts("\n");

    for (vector<AstCFunc*>::iterator it = m_dpis.begin(); it != m_dpis.end(); ++it) {
	AstCFunc* nodep = *it;
	if (nodep->dpiExportWrapper()) {
	    puts("#ifndef _VL_DPIDECL_"+nodep->name()+"\n");
	    puts("#define _VL_DPIDECL_"+nodep->name()+"\n");
	    puts(nodep->rtnTypeVoid()+" "+nodep->name()+" ("+cFuncArgs(nodep)+") {\n");
	    puts("// DPI Export at "+nodep->fileline()->ascii()+"\n");
	    puts("return "+topClassName()+"::"+nodep->name()+"(");
	    string args;
	    for (AstNode* stmtp = nodep->argsp(); stmtp; stmtp=stmtp->nextp()) {
		if (AstVar* portp = stmtp->castVar()) {
		    if (portp->isIO() && !portp->isFuncReturn()) {
			if (args != "") args+= ", ";
			args += portp->name();
		    }
		}
	    }
	    puts(args+");\n");
	    puts("}\n");
	    puts("#endif\n");
	    puts("\n");
	}
    }
}